DE102012213577A1 - Housing for lithium-ion battery utilized in e.g. electric car, has base plate, cover, and side surface that is arranged with narrow regions comprising respective portions arranged parallel to each other - Google Patents

Abstract

The housing has a base plate (11), a cover (12) and a side surface (13) that extends circumferentially between the bottom plate and the cover, where the side surface is arranged with a narrow region (14a). A portion (15a) of the narrow region faces the cover. Another portion (15b) of another narrow region (14b) faces the former portion with respect to the circumference of the side surface. The latter narrow region is formed in a flat manner. The former portion and the latter portion of respective narrow regions are arranged parallel to each other. Independent claims are also included for the following: (1) a battery (2) a battery arrangement.

Description

The present invention relates to a housing for a battery, a battery and a battery assembly, the housing having a bottom plate, a lid and a side surface extending circumferentially between the bottom plate and the lid, and wherein the side surface has at least one tapered region.

State of the art

It is becoming apparent that in the future both in stationary applications (for example in wind turbines), in vehicles (for example in hybrid and electric vehicles) and in the consumer sector (for example laptops and mobile phones), new battery systems will increasingly be used very high demands are placed on reliability, performance and service life.

An important parameter for performance is the specific energy. This has the unit watt-hours per kilogram (Wh / kg) and indicates how much energy can be stored in one kilogram of battery. It is therefore the desire of the manufacturers to reduce the weight of the battery in order to increase this quotient. Lithium-ion battery cells are sensitive to external influences such as air or moisture and must therefore be protected as much as possible from them.

The protection, for example, ensures a hardcase housing. It consists of two parts, the so-called "can plate" (housing) and the so-called "cap plate" (lid), which are welded together in the manufacturing process. Another form of housing represents the so-called "coffee bag cell", a housing made of aluminum composite film.

Not only lithium-ion battery cells, but also other chemical systems or galvanic systems may have a corresponding housing, such as nickel-metal-hydride cells or lithium-metal-polymer cells.

The traction batteries in hybrid and electric vehicles are usually modular. In this case, modules are formed from at least two individual cells (which are connected in series or in parallel), which in turn are combined to form larger subunits, so-called sub-units, which, for example, share a common cooling device. Two or more of these sub-units will ultimately build a complete battery. The modules and sub-units can also be arranged one above the other in several levels, depending on the installation space.

From the US 2009/0035652 A1 For example, a non-prismatic battery case is known in which the lower limit is narrower than the upper limit.

Disadvantage is that additional space is needed for the attachment or clamping of battery cells or that additional space is needed for the passage of required components and electrical cables or cooling lines.

Disclosure of the invention

According to the invention, a housing for a battery is provided with a bottom plate, a lid and a side surface extending circumferentially between the bottom plate and the lid, wherein the side surface has at least one tapering region in which the distance of the side surface of a in Reduced relative to the circumference opposite region of the side surface from the lid to the bottom plate, wherein a first portion of the tapering portion facing the lid and a second portion of the tapering portion facing the first portion with respect to the periphery of the side surface are formed flat and the first region and the second region are arranged parallel to each other.

For the purposes of the present invention, opposing areas of the side surface are characterized in that it is rotating about a half full circle, corresponding to 180 degrees, about an axis which is perpendicular to the bottom plate with respect to two dimensions and passes through a center of gravity of the housing. are arranged differently. The first and second regions are parallel to each other and spaced from each other. The circumference corresponds to a sectional curve formed by cutting the side surface of the housing from a plane which is perpendicular to the axis with respect to two dimensions. Thus, "opposite" implies a similar height on both opposite sides, thus implying symmetry of the two side regions.

For the purposes of the invention, the term "battery" also applies to a galvanic element, that is to say both a cell network and a single cell, and furthermore, in particular, rechargeable secondary batteries.

The invention provides as an advantage that such, limited to a few areas, volume reduction of the housing allows use of the inventively released volume.

In a preferred embodiment, the side surface of the housing comprises four planar major surfaces, each two major surfaces spaced parallel opposite each other and adjacent major surfaces are arranged at right angles to each other and also at least one of the major surfaces has a tapering region.

One advantage is the possibility of being able to stack a plurality of such housings wall-to-wall and nevertheless to have volume which has become vacant according to the invention.

Preferably, the first region of the housing extends over at least 10%, more preferably at least 20%, even more preferably at least 30%, also preferably at least 50% or more preferably at least 70% of the distance between the lid and the bottom plate.

A resulting advantage is that elements which can be expressed as a percentage of the distance between the cover and the bottom plate, which is useful, for example, for forming housing categories, can be arranged in the volume area which has become vacant.

It is also conceivable that the side surface of the housing at the lower end of the first region kinks.

The advantage of this is that a kink has a strong curvature and thus a change in direction in the side surface is possible in the smallest space, which is favorable for the largest possible inventively freed volume.

In a particularly preferred variant of the housing shape, an extension of the bottom plate along its longitudinal axis is shorter than an extension of the lid along its longitudinal axis.

The invention is based on the finding that a volume freed up according to the invention is spanned by a height, a length and a width, the preferred variable parameter being a length difference around which the bottom plate is shorter than the cover.

An advantage achieved thereby is the possibility of being able to stack a plurality of such housing wall on wall and on a base, wherein the bottom plates stand on the surface and yet have inventively freed volume.

According to a further aspect of the invention, a battery is disclosed with a housing according to at least one of the aforementioned variants.

As the battery, lithium-ion secondary cells are preferable.

The advantage of a battery with a housing according to the invention is the possibility of using the space vacated according to the invention for elements which are useful in connection with a battery.

In a preferred embodiment of the battery, an extension of a layer coil along its longitudinal axis in the region of the bottom plate is shorter than in the region of the lid.

For the purposes of the invention, the layer winding is a layered structure of the chemically-physically active components of a battery in order to generate electricity. The layer coil preferably comprises electrodes, an electrode collector foil, an electrolyte and / or a polymer. Preferably, in a region facing the bottom plate, a projection of the electrode collector foil is cut off. This is not needed because a collector fork is welded only in a region facing the lid and thus the cell housing can be made narrower in the area facing the bottom plate.

As an advantage results in a material saving, since in particular the pointing to the edge of the battery case metal parts of the electrodes or the contacts to the electrodes are reduced, which proves to be favorable in terms of reduced material price as well as with respect to the reduced inertial mass.

In a further preferred embodiment of the battery, an extension of the electrodes along their longitudinal direction in the region of the bottom plate is shorter than in the region of the lid.

A material saving is also advantageous here, since in particular the metal parts of the electrodes or the contacts to the electrodes pointing to the edge of the battery housing are reduced, which proves to be favorable with regard to the reduced material price as well as to the reduced inertial mass.

It is also possible that the cover of the battery has two recesses, and an electrical connection terminal is guided through each recess.

As an advantage, the distance between two terminal terminals achieved by which is particularly useful for the interconnection of multiple batteries.

According to another aspect of the invention, a battery assembly is disclosed wherein batteries having at least one of the aforementioned features are stacked side by side in at least one spatial direction and at least one taper region of a first battery forms a channel with another adjacent side region of a second, adjacent battery is limited to the sides and up through the tapering region and the adjacent side region, wherein in this channel, a fastener, a conduit for information, electricity or heat transfer or a cooling element is arranged.

The invention is based on the finding that, in particular with rectangular stacking of several batteries and thus despite effective spatial arrangement of batteries, an inventive additional space can be used as a route or channel.

As a result of the resulting advantage in particular the possibility to use the channel for the accommodation of heat, signal or power lines as well as for the accommodation of fasteners, and thus to be able to use space vacated according to the invention.

Preferably, the tapering region of the housing has a (particularly preferably flat) surface in the region facing the cover, this flat surface in the lower region inwards, preferably at an angle between 20 and 170 °, more preferably at an angle between 40 and 130 °, even more preferably at an angle between 60 and 90 ° and particularly preferably at right angles, kinks. Alternatively, the tapering region of the housing preferably has a flat surface in the region facing the cover, this flat surface merging in the lower region into an outwardly curved curve, wherein the rounding preferably has a radius between 0.3 mm and 100 mm, more preferably between 1 mm and 30 mm and more preferably between 3 mm and 10 mm. Preferably, the tapered region having said rounded portion preferably has a further inwardly curved curve (located between the outer curved curve and the cover), this rounding preferably having a radius between 0.3 mm and 100 mm, more preferably between 1 mm and 30 mm and more preferably between 3 mm and 10 mm.

Preferably, the tapering region has an (optionally further) (particularly preferably flat) surface which extends from the cover, this flat surface in the upper region outwards, preferably at an angle between 20 and 170 °, more preferably at an angle between 40 and 130 °, more preferably at an angle between 60 and 90 ° and most preferably at right angles, kinks. Particularly preferably, the two flat surfaces of the tapering region are oriented parallel to each other, wherein the lower planar surface is arranged offset inwards.

An arrangement of batteries with housing according to the invention is preferably carried out such that the arrangement along a direction of extension of a longitudinal axis of each battery is almost completely, and thus adjacent areas of the adjacent shorter battery sides of adjacent batteries form a volume which corresponds to a channel having a length which an n-times a width of a short battery side corresponds, wherein the width extends horizontally and perpendicular to the extension direction of the longitudinal axis of the battery and n is the number of batteries stacked one behind the other in the extension direction of a longitudinal axis of each battery.

The first distance of the opposing (facing the lid) portions of two tapered portions of a battery case is preferably between 105 and 150%, more preferably between 110 and 130% and even more preferably between 115 and 125% of the second distance of the opposing (facing the bottom plate ) Areas.

As an advantage, it follows that the preferred spacing ratio represents a particularly efficient utilization of the installation space not required by the electrode collector foils in the lower area, which leads to a high energy density of the battery on the one hand and to a large utility channel on the other hand.

drawings

Embodiments of the invention will be explained in more detail with reference to the drawings and the description below. Show it:

1 a battery with housing according to the invention according to a first preferred embodiment,

2 an exploded view of a housing according to the invention according to a second embodiment variant,

3 a battery stack with inventive channel,

4 a battery with inventive housing according to a third preferred embodiment, and

5 a battery with inventive housing according to a fourth preferred embodiment.

Detailed description of the figures

1 shows a two-dimensional schematic representation of a battery with housing according to the invention according to a first preferred embodiment variant. In the lower area is a bottom plate 11 and above that, within the housing, a laminar wrap 21 arranged, which is designed to realize electrochemical processes of a rechargeable battery. A lid 12 closes the housing over a large area towards the upper side. A side surface 13 surrounds the layer wrap 21 in all areas, which are not covered by the bottom plate 11 , the lid 12 or electrical connection terminals 24 . 25 are covered, leaving the housing except for the electrical contacts 24 . 25 the layer wrap 21 completely encloses. To carry out the contacts 24 . 25 There are two holes in the lid 12 brought in.

As part of the side surface 13 is a left taper area 14a provided that a symmetry to the right tapering area 14b has. Both areas 14a . 14b lie opposite each other and point in a lid 12 facing area 15a . 15b a first distance d1 and in one of the bottom plate 11 facing area 16a . 16b a second distance d2 from each other. In each case as subregions of the side surface 13 is a level area 15a which one the lid 12 facing part of the left taper area 14a is, at a distance d1 a right, the lid 12 facing, flat area 15b parallel opposite. In the left rejuvenation area 14a , outside the range 15a , but as part of the side surface 13 , the bottom plate 11 facing, there is a left recess area 16a at a distance d2 to a right-hand recess area 16b which is also the part of the side surface 13 and the bottom plate 11 is facing. The recessed areas 16a . 16b are not limited to flat areas, but contain a kink and a curvature of the side surface 13 , starting from the direction of the lid 12 to the bottom plate 11 going on, the curvature corresponding to a center outside the housing, as opposed to a curvature defining the side surface 13 in the bottom plate 11 ignore and thereby has a corresponding center within the housing.

A left electrode 26 and a right electrode 27 , which from the layer winding 21 protrude out through recesses in the lid 12 electrically to the connection terminals 24 and 25 guided.

The spatial extent of the layer winding 21 which comprises an electrode collector foil is in two of the bottom plate 11 facing areas 16a . 16b along its longitudinal axis, ie in the direction of the left and in the direction of the right, shortened compared to its extension in the lid 12 facing areas 15a and 15b because a collector fork is only in the upper area 15a . 15b is welded. 2 is a three-dimensional schematic exploded view of a housing according to the invention according to a second preferred embodiment, consisting of a bottom plate 11 , a side surface 13 , and a lid 12 with recesses 22 and 23 , The left taper area 14a as part of the side surface 13 contains an upper level section 15a , which at a distance d1 a right upper planar portion 15b , as part of a right taper area 14b , lies parallel opposite.

In both of the bottom plate 11 facing, lower areas 16a . 16b the two opposite taper areas 14a . 14b , that is, below the upper flat parts 15a and 15b , owns the side surface 13 two right-angled creases. It has the lower left area 16a a distance d2 from the lower right area 16b where d2 is less than d1 and both d1 and d2 are greater than zero.

The front 18 , as part of the side surface 13 , is a flat surface, as is the back 19 , Even if the 2 due to the exploded view the front 18 and the back 19 shows horizontally separated, the housing according to the invention has a front side 18 and a back 19 , which each without interruption from the bottom plate 11 to the lid 12 extend.

3 shows a battery stack, in particular two side by side on a base 32 arranged batteries 30 and 31 , As every battery of the invention 30 . 31 preferably in each case two rejuvenation areas 14a . 14b has two adjacent batteries on short sides 31 . 31 the rejuvenation areas 14a . 14b Both batteries face each other and form a cavity, as a channel 28 or path named. Thus, cables can 29 be guided or arranged for information, power, heat and / or fasteners in this channel, preferably along several consecutively stacked battery pairs.

The length of the bottom plate 11 , ie the extent along its longitudinal axis, corresponds to the distance d2, while the length of the lid 12 , ie the extent along its longitudinal axis, corresponds to the distance d1. The measure around which the bottom plate 11 shorter than the lid corresponds to the width of the channel 28 , 4 and 5 show in two-dimensional schematic representation further preferred embodiments of a battery with inventive housing.

The side surfaces 16a and 16b are in the area of the bottom plate 11 formed outwardly, preferably in the form of a triangle or quadrilateral. In these variants, the housing can preferably be produced by means of hydroforming or by a subsequent attachment of a molded part. By way of example, this formation of the lower side surfaces can be a fixation of the battery to achieve a vertical movement.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2009/0035652 A1 [0007]

Claims (10)

Housing for a battery comprising: (i) a bottom plate ( 11 ); (ii) a lid ( 12 ); and (iii) a side surface ( 13 ), which circulates between the bottom plate ( 11 ) and the lid ( 12 ), wherein the side surface ( 13 ) at least one regeneration area ( 14a ), in which the distance (d1, d2) of the side surface ( 13 ) from a region opposite to the circumference ( 15b ) of the side surface ( 13 ) from the lid ( 12 ) to the bottom plate ( 11 ), characterized in that (iv) a first region ( 15a ) of the rejuvenation area ( 14a ), the lid ( 12 ) and a second area ( 15b ) of the rejuvenation area ( 14b ), the first area ( 15a ) in relation to the circumference of the side surface ( 13 ) is opposite, plan are formed; and (v) the first area ( 15a ) and the second area ( 15b ) are arranged parallel to each other. Housing according to claim 1, wherein the side surface ( 13 ) four plan-trained main surfaces ( 15a . 15b . 18 . 19 ), wherein in each case two main surfaces ( 15a . 15b . 18 . 19 ) are spaced from each other in parallel, with adjacent major surfaces ( 15a . 18 ) 15a . 19 ) 15b . 18 ) 15b . 19 ) are arranged at right angles to each other, wherein at least one of the main surfaces ( 15a . 15b . 18 . 19 ) a rejuvenation area ( 14a . 14b ) having. Housing according to at least one of the preceding claims, wherein the first area ( 15a ) over at least 20% of the distance between the lid ( 12 ) and the bottom plate ( 11 ). Housing according to at least one of the preceding claims, wherein the side surface ( 13 ) at the lower end of the first area ( 15a ) kinks. Housing according to at least one of the preceding claims, wherein a length of the bottom plate ( 11 ), which along a longitudinal axis of the bottom plate ( 11 ) is shorter than a length of the lid ( 12 ), which along a longitudinal axis of the lid ( 12 ). Battery with a housing according to at least one of the preceding claims. A battery according to claim 6, wherein a spatial extent of a layer coil ( 21 ), which along a longitudinal axis of the layer coil ( 21 ), in the region of the bottom plate ( 11 ) is shorter than in the area of the lid ( 12 ). Battery according to claim 6 or 7, wherein a spatial extent of the electrodes ( 26 . 27 ), which extend along a longitudinal axis of the electrodes ( 26 . 27 ), in the region of the bottom plate ( 11 ) is shorter than in the area of the lid ( 12 ). Battery according to at least one of claims 6 to 8, wherein the lid ( 12 ) two recesses ( 22 . 23 ), and by each recess ( 22 . 23 ) an electrical connection terminal ( 24 . 25 ) is guided. Battery arrangement, wherein at least two batteries ( 30 . 31 ) according to one of the preceding claims 6 to 9 are stacked next to each other in at least one spatial direction and at least one rejuvenation area ( 14b ) of a first battery ( 30 ) with another, adjacent side area ( 14a ) of a second, adjacent battery ( 31 ) a channel ( 28 ) formed by adjacent subregions ( 16b . 16a ) of the side surfaces ( 13 ) neighboring batteries ( 30 . 31 ) and in this channel ( 28 ) a fastener, a conduit ( 29 ) is arranged for information, electricity or heat transport and / or a cooling element.

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